US11427884B2 - Method for treating fluorine-containing rare earth mineral particles - Google Patents

Method for treating fluorine-containing rare earth mineral particles Download PDF

Info

Publication number
US11427884B2
US11427884B2 US16/630,311 US201916630311A US11427884B2 US 11427884 B2 US11427884 B2 US 11427884B2 US 201916630311 A US201916630311 A US 201916630311A US 11427884 B2 US11427884 B2 US 11427884B2
Authority
US
United States
Prior art keywords
rare earth
sulfuric acid
fluorine
batch
mineral particles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US16/630,311
Other versions
US20210062295A1 (en
Inventor
Jianguo Cui
Zhe Wang
Ruien Hou
Dong Li
Meng Xu
Ting Gao
Xiaoli Hao
Bo Li
Yang Zhang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Baotou Rare Earth Research Institute
Ruike Rare Earth Metallurgy and Functional Materials National Engineering Research Center Co Ltd
Original Assignee
Baotou Rare Earth Research Institute
Ruike Rare Earth Metallurgy and Functional Materials National Engineering Research Center Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Baotou Rare Earth Research Institute, Ruike Rare Earth Metallurgy and Functional Materials National Engineering Research Center Co Ltd filed Critical Baotou Rare Earth Research Institute
Assigned to NATIONAL ENGINEERING RESEARCH CENTRE OF RUIKE RARE EARTH METALLURGY AND FUNCTION MATERIALS CO., LTD., Baotou Research Institute of Rare Earths reassignment NATIONAL ENGINEERING RESEARCH CENTRE OF RUIKE RARE EARTH METALLURGY AND FUNCTION MATERIALS CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CUI, JIANGUO, GAO, TING, HAO, Xiaoli, HOU, Ruien, LI, BO, LI, DONG, WANG, ZHE, XU, MENG, ZHANG, YANG
Publication of US20210062295A1 publication Critical patent/US20210062295A1/en
Application granted granted Critical
Publication of US11427884B2 publication Critical patent/US11427884B2/en
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
    • C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
    • C22B3/06—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions
    • C22B3/08—Sulfuric acid, other sulfurated acids or salts thereof
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B59/00—Obtaining rare earth metals

Definitions

  • the present invention relates to a method for treating fluorine-containing rare earth mineral particles, in particular to a method for treating bastnaesite-containing rare earth mineral particles.
  • Rare earth minerals mainly exist in the form of bastnaesite, mixed rare earth concentrate (bastnaesite and monazite), beach placer (monazite) and weathing crust strain amass-type rare earth ore.
  • the representatives of bastnaesite are from Mountain Pass mine in the United States, Mianning rare earth mine in Sichuan province and Weishanhu mine in Shandongzhou in China.
  • the typical representative of mixed type rare earth mineral is Baiyenebo rare earth minerals from Baotou area in Inner Mongolia in China. Therefore, it is of great significance to study the smelting separation technology of bastnaesite minerals. At present, the smelting technology of bastnaesite or bastnaesite in mixed type rare earth minerals has attracted more and more attention.
  • rare earth resources can be extracted with an air oxidizing roasting-hydrochloric acid dissolution technology.
  • Bastnaesite mineral is decomposed into rare earth fluoride and rare earth oxide by oxidizing roasting.
  • concentration of hydrochloric acid and process of adding hydrochloric acid are controlled when the roasted ores are preferentially dissolved with hydrochloric acid, so as to extract trivalent rare earth and preliminarily separate from tetravalent cerium.
  • Components such as cerium fluoride and cerium dioxide are retained in the residue, and can be used to prepare low-grade ferrosilicon alloy, or to extract tetravalent cerium with concentrated hydrochloric acid under the action of thiourea reductant.
  • This process is widely used in the treatment of bastnaesite from Mianning in Sichuan province. It can simply recover valuable rare earth at low cost.
  • the problem of the above technical solution is that fluorine resources are not effectively used and rare earth resources are not completely extracted.
  • rare earth resources can be extracted with air oxidizing roasting-sulfuric acid dissolution technology.
  • CN1683568A discloses a method of treating bastnaesite and separating cerium. Firstly, the bastnaesite concentrate is oxidizing roasted at 300-1000° C. to obtain bastnaesite calcine; the rare earth is leached out from the bastnaesite calcine with sulfuric acid, which is subjected to separation and reduction by coordination precipitant to separate trivalent rare earth elements from tetravalent rare earth elements, and to separate tetravalent cerium from tetravalent thorium.
  • the problem of the above technical solution is that the bastnaesite concentrate must be oxidizing roasted at high temperature, and thus the process is too complicated.
  • the mixed type rare earth minerals 90% of which are subjected to decomposition by concentrated sulfuric acid roasting process at high temperature.
  • the mixed type rare earth minerals and concentrated sulfuric acid are roasted at high temperature of 500-1000° C.
  • rare earth minerals and concentrated sulfuric acid contact and react, the solid-liquid phase changes into solid phase very quickly, and the reaction efficiency is very high. Therefore, the reaction makes high requirements on the particle size of raw mineral materials.
  • the size of mineral particles is greater than 200 mesh, the reaction rate will rapidly drop or the reaction will be terminated after a reaction on the surface is over.
  • elements of fluorine and silicon in minerals and sulfur oxides from sulfuric acid decomposition enter the tail gas system, which makes it difficult to recycle fluorine resources.
  • CN106978532A discloses a method for extracting rare earth, fluorine and thorium from fluorine-contained rare earth minerals by concentrated sulfuric acid.
  • the method comprises the following steps: the fluorine-contained rare earth minerals are mixed with the concentrated sulfuric acid; single fluorine-contained rare earth minerals or mixed rare earth concentrates contain 50-70 mass % of rare earth oxides; H 2 SO 4 of the concentrated sulfuric acid is more than 90 mass %; the weight ratio of the fluorine-contained rare earth minerals to the concentrated sulfuric acid is 1:0.6-1.0; a mixture is fired for 120-300 min under the condition of 120-180° C.; a reaction product is leached with water, and then aqueous leaching liquor is neutralized to reach a pH value of 3.5-4.5 to form sulfuric acid rare earth solution and iron thorium enriched matters.
  • the above technical solution realizes the transformation from solid-liquid phase to solid-solid phase, increases the reaction time, and realizes the preferential decomposition of bastnaesite.
  • CN102534269A discloses a method for comprehensively recycling various rare earth from rare earth materials containing fluorine, comprising the following steps: a. stirring the rare earth materials containing the fluorine with sulfuric acid, wherein hydrofluoric acid gas generated in the stirring process is used for preparing cryolite or hydrofluoric acid; b. leaching the stirred materials with water to obtain sulfuric rare earth solution.
  • the sulfuric acid in step a is sulfuric acid with a concentration greater than 98%; the weight ratio of rare earth oxide in the rare earth material containing fluorine and sulfuric acid is 1:1.5-2; the addition amount of water during aqueous leaching in step b is controlled so that the concentration of rare earth in the aqueous leaching liquor is controlled at 90-110 g/L. Because the rare earth material containing fluorine and sulfuric acid react violently and release heat in the mixing process, the materials have already been in a semi-dry state.
  • the above technical solution still has the following problems: first, due to too high concentration of sulfuric acid during mixing the reaction between concentrated sulfuric acid and bastnaesite is violent followed by a reaction rate changing greatly, so that it is difficult to control the reaction; second, the rare earth materials containing fluorine and sulfuric acid are mixed to form a semi-dry state, so the sulfuric acid is not easy to be recycled; third, it can treat only the activated bastnaesite after calcination or other reactions, but not the inactivated bastnaesite or mixed type rare earth concentrate.
  • the fluorine-containing rare earth mineral particles are decomposed by the liquid-solid phase mixing reaction in a lower concentration of sulfuric acid solution at a lower temperature, so as to realize the rapid decomposition of the fluorine-containing rare earth mineral particles.
  • the reaction is easy to be controlled, and the residual acid resources are recycled.
  • the purpose of the present invention is to provide a method for treating fluorine-containing rare earth mineral particles, wherein absolute excess sulfuric acid solution with a lower concentration is used to decompose the fluorine-containing rare earth mineral particles by liquid-solid phase mixing reaction at a lower temperature, so as to realize the rapid decomposition of fluorine-containing rare earth mineral particles.
  • the reaction is easy to be controlled, and the residual acid resources are recycled.
  • the present invention provides a method for treating fluorine-containing rare earth mineral particles, comprising the following steps:
  • first batch of fluorine-containing rare earth mineral particles and the i th batch of fluorine-containing rare earth mineral particles are rare earth mineral particles without performing roasting decomposition.
  • step (1) the liquid-solid reaction is performed under continuous stirring, the reaction temperature is 100-180° C., and the reaction time is 0.5-5 hours.
  • step (1) the liquid-solid reaction is performed under continuous stirring, the reaction temperature is 120-180° C., and the reaction time is 0.5-2 hours.
  • the weight ratio of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is 3-8:1.
  • the first batch of fluorine-containing rare earth mineral particles and the i th batch of fluorine-containing rare earth mineral particles are selected from one or two of the following: (A) bastnaesite, (B) mixed type rare earth concentrate of bastnaesite and monazite.
  • the first batch of fluorine-containing rare earth mineral particles and the i th batch of fluorine-containing rare earth mineral particles have a particle size of less than 150 mesh.
  • the first batch of fluorine-containing rare earth mineral particles and the i th batch of fluorine-containing rare earth mineral particles have a particle size of less than 200 mesh.
  • the sulfuric acid concentration of the first sulfuric acid solution is 50-85 wt %; and in step (4) the second sulfuric acid solution is added to the acid filtrate so that the sulfuric acid concentration of the acid filtrate is 50-85 wt %.
  • the sulfuric acid concentration of the first sulfuric acid solution is 60-75 wt %; and in step (4), the second sulfuric acid solution is added to the acid filtrate so that the sulfuric acid concentration of the acid filtrate is 60-75 wt %.
  • the concentration of the rare earth sulfate in the rare earth sulfate aqueous leaching liquor is 20-45 g/L, calculated based on the rare earth oxide REO.
  • absolute excess sulfuric acid solution with a lower concentration is used to decompose the fluorine-containing rare earth mineral particles by liquid-solid phase mixing reaction at a lower temperature, so as to realize the rapid decomposition of the fluorine-containing rare earth mineral particles.
  • the reaction is easy to be controlled, and the residual acid resources are recycled.
  • the liquid-solid reaction is circularly applied to directly decompose the inactivated bastnaesite or mixed type rare earth concentrate; thereby the cost of rare earth extraction is significantly reduced.
  • the weight ratio of sulfuric acid to fluorine-containing rare earth mineral particles is 3-5:1, and the following technical problem is solved by using absolute excess sulfuric acid solution with a lower concentration: a great change in reaction rate of concentrated sulfuric acid and bastnaesite, and it is difficult to control the reaction.
  • select from or “selected from” refers to the selection of individual components or the combination of two (or more) components.
  • the method for treating fluorine-containing rare earth mineral particles comprising the following steps: (1) performing liquid-solid reaction of the first batch of fluorine-containing rare earth mineral particles and the first sulfuric acid solution; (2) separating solid phase and liquid phase to obtain acid filtrate and acid residue; (3) treating the acid residue; (4) adding the second sulfuric acid solution to the acid filtrate, and then circularly executing the steps (1)-(3) for treating the i th batch of fluorine-containing rare earth mineral particles, wherein “i” is a natural number greater than or equal to 2.
  • both the first batch of fluorine-containing rare earth mineral particles and the i th batch of fluorine-containing rare earth mineral particles are selected from one or two of the following: (A) bastnaesite, (B) mixed type rare earth concentrate of bastnaesite and monazite.
  • the first batch of fluorine-containing rare earth mineral particles and the i th batch of fluorine-containing rare earth mineral particles are rare earth mineral particles without performing roasting decomposition.
  • the method of the present invention is suitable to fluorine-containing rare earth mineral particles that have not been subjected to roasting decomposition; thereby the cost of rare earth extraction can be significantly reduced.
  • the mixed raw material is the first batch of fluorine-containing rare earth mineral particles and the first sulfuric acid solution.
  • the sulfuric acid concentration of the first sulfuric acid solution is 40-85 wt %; preferably, the sulfuric acid concentration of the first sulfuric acid solution is 50-85 wt %; more preferably, the sulfuric acid concentration of the first sulfuric acid solution is 60-75 wt %.
  • the weight ratio of the sulfuric acid (i.e., solute) in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is 2-10:1; preferably, the weight ratio of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is 3-8:1; more preferably, the weight ratio of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is 3-5:1.
  • the weight ratio of the sulfuric acid in the first sulfuric acid solution to the bastnaesite from Mianning in Sichuan province is 3.4-3.8:1.
  • the weight ratio of the sulfuric acid in the first sulfuric acid solution to the mixed rare earth concentrate from Baiyenebo is 4-5:1.
  • the liquid-solid reaction is performed under continuous stirring.
  • General mechanical agitation may be used.
  • the liquid-solid reaction temperature is 100-180° C.; preferably, the liquid-solid reaction temperature is 120-180° C.; more preferably, the liquid-solid reaction temperature is 130-180° C.
  • the liquid-solid reaction time is 0.5-5 hours; preferably, the liquid-solid reaction time is 0.5-3 hours; more preferably, the liquid-solid reaction time is 0.5-2 hours.
  • Steam may be generated during liquid-solid reaction, and it contains a lot of hydrofluoric acid gas.
  • the hydrofluoric acid gas is condensed and absorbed through the tail gas system to obtain hydrofluoric acid products.
  • the liquid-solid reaction temperature is 140-150° C., and the reaction time is 1-1.5 hours.
  • the liquid-solid reaction temperature is 170-180° C., and the reaction time is 0.5-1 hours;
  • the liquid-solid reaction temperature is 150-160° C., and the reaction time is 1-1.5 hours;
  • the liquid-solid reaction temperature is 130-135° C., and the reaction time is 1.5-2 hours; for each one of the following 15 rounds of circular execution, the liquid-solid reaction temperature is 130-135° C., and the reaction time is 1.5-2 hours.
  • step (2) of the method according to the present invention solid phase and liquid phase are separated after the liquid-solid reaction to obtain acid filtrate and acid residue.
  • Rare earth products can be obtained by treating the acid residue.
  • absolute excess sulfuric acid solution with a lower concentration is used.
  • the sulfuric acid solution is of a greatly excessive amount.
  • the fluorine-containing rare earth mineral particles are completely immersed in the sulfuric acid solution. There are relatively large amount of sulfuric acid solutions left after the reaction, and the remaining sulfuric acid solution (acid filtrate) can be recycled.
  • solid phase and liquid phase are separated after the reaction, and the first batch of acid filtrate and the first batch of acid residue are obtained.
  • solid phase and liquid phase are separated after the reaction, and the first batch of acid filtrate and the first batch of acid residue are obtained.
  • step (3) of the method according to the present invention the acid residue is leached with water to obtain aqueous leaching liquor of rare earth sulfate and aqueous leaching residue.
  • the bastnaesite decomposition rate is ⁇ 95%, calculated based on the rare earth oxide (REO) in the aqueous leaching residue; in case of that fluorine-containing rare earth mineral particles are the mixed type rare earth concentrate of bastnaesite and monazite, the bastnaesite decomposition rate is ⁇ 95%, calculated based on the F content in the aqueous leaching residue.
  • the fluorine-containing rare earth mineral particles are bastnaesite from Mianning in Sichuan province, the bastnaesite decomposition rate is ⁇ 96% in the multi-round of circular execution, calculated based on the rare earth oxide (REO) in the aqueous leaching residue.
  • the fluorine-containing rare earth mineral particles are the mixed type rare earth concentrate from Baiyenebo, the bastnaesite decomposition rate is ⁇ 96% in the multi-round of circular execution, calculated based on the F content in the aqueous leaching residue.
  • step (3) of the method according to the present invention when the acid residue is leached with water, the amount of water is 10-50 times of the weight of the first batch of fluorine-containing rare earth mineral particles; preferably, the amount of water is 10-35 times of the weight of the first batch of fluorine-containing rare earth mineral particles; more preferably, the amount of water is 15-25 times of the weight of the first batch of fluorine-containing rare earth mineral particles.
  • liquid-solid reaction is performed circularly to decompose bastnaesite from Mianning in Sichuan province, in which the first batch of acid residue is leached with 1500-2000 mL of water.
  • the amount of water is 15-20 times of the weight of bastnaesite from Mianning in Sichuan province.
  • liquid-solid reaction is performed circularly to decompose the mixed rare earth concentrate from Baiyenebo, in which the first batch of acid residue is leached with 1500-2000 mL of water.
  • the amount of water is 15-20 times of the weight of the mixed rare earth concentrate from Baiyenebo.
  • the concentration of rare earth sulfate is 20-45 g/L calculated based on the rare earth oxide (REO), preferably 25-40 g/L, more preferably 30-35 g/L.
  • REO rare earth oxide
  • liquid-solid reaction is performed circularly to decompose bastnaesite from Mianning in Sichuan province
  • the first batch of acid residue is leached with 1500-2000 mL of water
  • the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 25.0-26.7 g/L calculated based on the rare earth oxide (REO)
  • the second batch of acid residue is leached with 1500-2000 mL of water
  • the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 28.0-30.2 g/L calculated based on the rare earth oxide (REO)
  • the third batch of acid residue is leached with 1500-2000 mL of water
  • the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 32-34.7 g/L calculated based on the rare earth oxide (REO)
  • the fourth batch of acid residue is leached with 1500
  • liquid-solid reaction is performed circularly to decompose the mixed rare earth concentrate from Baiyenebo
  • the first batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 22-23.3 g/L calculated based on the rare earth oxide (REO)
  • the second batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 28.0-30.7 g/L calculated based on the rare earth oxide (REO)
  • the third batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 32-34.5 g/L calculated based on the rare earth oxide (REO); after the following 15-18 rounds of circular execution, the concentration of rare earth s
  • step (4) of the method according to the present invention after the second sulfuric acid solution is added to the acid filtrate, circularly executing the steps (1)-(3) for treating the i th batch of fluorine-containing rare earth mineral particles.
  • the character “i” is a natural number greater than or equal to 2, for example, it can be 2, 3, 4, 5, 6, 7, 8 and so on.
  • the initial mass fraction of sulfuric acid solution is 40-85 wt %; preferably, before each round of liquid-solid reaction, the initial mass fraction of sulfuric acid solution is 50-85 wt %; more preferably, before each round of liquid-solid reaction, the initial mass fraction of sulfuric acid solution is 60-75 wt %.
  • the sulfuric acid concentration of the second sulfuric acid solution is ⁇ 90 wt %; preferably, the sulfuric acid concentration of the second sulfuric acid solution is ⁇ 95 wt %; more preferably, the sulfuric acid concentration of the second sulfuric acid solution is ⁇ 98 wt %.
  • 60-72 g of concentrated sulfuric acid with concentration of 98 wt % is added to the first batch of acid filtrate, calculated based on treating 100 g of the second batch of bastnaesite.
  • 60-68 g of concentrated sulfuric acid with concentration of 98 wt % is added into the second batch of acid filtrate, calculated based on treating 100 g of the third batch of bastnaesite.
  • 65-72 g of concentrated sulfuric acid with concentration of 98 wt % is added into the third batch of acid filtrate, calculated based on treating 100 g of the fourth batch of bastnaesite.
  • 53-55 g of concentrated sulfuric acid with concentration of 98 wt % is added into the acid filtrate in the last round of each round, calculated based on treating 100 g of the i th batch of bastnaesite.
  • the temperature of liquid-solid reaction in each circular execution is 100-180° C., preferably 120-180° C., more preferably 130-180° C.
  • the time of liquid-solid reaction in each circular execution is 0.5-5 hours, preferably 0.5-3 hours, more preferably 0.5-2 hours.
  • Steam may be generated during liquid-solid reaction of each circular execution, and it contains a lot of hydrofluoric acid gas.
  • the hydrofluoric acid gas is condensed and absorbed through the tail gas system to obtain hydrofluoric acid products.
  • solid phase and liquid phase are separated after the liquid-solid reaction, and acid filtrate and acid residue are obtained. Rare earth products can be obtained by treating the acid residue.
  • the method for treating fluorine-containing rare earth mineral particles according to the present invention also comprises the step of crushing fluorine-containing rare earth mineral particles.
  • the fluorine-containing rare earth mineral particles are crushed to a particle size of less than 150 mesh; preferably, the fluorine-containing rare earth mineral particles are crushed to a particle size of less than 200 mesh. This can facilitate the decomposition of the fluorine-containing rare earth mineral particles. If the fluorine-containing rare earth mineral particles have a particle size of less than 150 mesh, they need not to be crushed, and thus the crushing procedure can be omitted.
  • the bastnaesite is crushed to a particle size of less than 150 mesh to obtain the bastnaesite particles.
  • the particle size of mixed type rare earth concentrate of bastnaesite and monazite is less than 200 mesh.
  • the crushing of the bastnaesite from Mianning in Sichuan province the bastnaesite from Mianning in Sichuan province with REO content of 68.2 wt % was crushed to a particle size of less than 150 mesh, and the bastnaesite particles were obtained.
  • the first batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor of rare earth sulfate and the aqueous leaching residue were obtained.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 26.7 g/L calculated based on REO.
  • the decomposition rate of bastnaesite is 98.2% calculated based on REO in the aqueous leaching residue.
  • the second batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 30.2 g/L calculated based on REO.
  • the decomposition rate of bastnaesite is 96.7% calculated based on REO in the aqueous leaching residue.
  • the third batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 34.7 g/L calculated based on REO.
  • the decomposition rate of bastnaesite is 96.3% calculated based on REO in the aqueous leaching residue.
  • the fourth batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 33.6 g/L calculated based on REO.
  • the decomposition rate of bastnaesite is 96.5% calculated based on REO in the aqueous leaching residue.
  • treating conditions for each round of circular execution was as follows: the addition amount of concentrated sulfuric acid with a concentration of 98 wt % was 53-55 g, the initial concentration of sulfuric acid was 70 wt %, the reaction temperature was 140° C., and the reaction time was 1 hour.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 32.5-33 g/L calculated based on REO.
  • the mixed rare earth concentrate from Baiyenebo the mixed rare earth concentrate from Baiyenebo has a REO content of 61.9 wt % and a particle size of less than 200 mesh.
  • the mixed rare earth concentrate from Baiyenebo is the mixed type rare earth concentrate of bastnaesite and monazite.
  • 100 g of the mixed rare earth concentrate from Baiyenebo without performing roasting decomposition was mixed with 590 g of sulfuric acid solution with a concentration of 85 wt % (the weight ratio of sulfuric acid to mixed rare earth concentrate from Baiyenebo is 5:1); the mixture was heated with stirring, and reacted at 180° C. for 0.5 hour, and steam was condensed and absorbed through tail gas system to obtain hydrofluoric acid products.
  • the solid phase and the liquid phase were separated after the liquid-solid reaction, and the first batch of acid filtrate and the first batch of acid residue were obtained.
  • the first batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 23.3 g/L calculated based on REO.
  • the decomposition rate of bastnaesite is 97.5% calculated based on the F content in the aqueous leaching residue.
  • 100 g of the second batch of mixed rare earth concentrate from Baiyenebo with REO content of 61.9 wt % was treated with the first batch of acid filtrate under stirring.
  • the initial concentration of sulfuric acid was 73 wt %
  • the reaction temperature was 150° C.
  • the reaction time was 1 hour.
  • the solid phase and the liquid phase were separated after the liquid-solid reaction, and the second batch of acid filtrate and the second batch of acid residue were obtained.
  • the second batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 30.7 g/L calculated based on REO.
  • the decomposition rate of bastnaesite is 96.2% calculated based on the F content in the aqueous leaching residue.
  • 100 g of the third batch of mixed rare earth concentrate from Baiyenebo with REO content of 61.9 wt % was treated with the second batch of acid filtrate under stirring.
  • the initial concentration of sulfuric acid was 64 wt %
  • the reaction temperature was 130° C.
  • the reaction time was 2 hour.
  • the solid phase and the liquid phase were separated after the liquid-solid reaction, and the third batch of acid filtrate and the third batch of acid residue were obtained.
  • the third batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 34.5 g/L calculated based on REO.
  • the decomposition rate of bastnaesite is 97.7% calculated based on the F content in the aqueous leaching residue.
  • treating conditions for each round of circular execution was as follows: the addition amount of concentrated sulfuric acid with a concentration of 98 wt % was 53-55 g, the initial concentration of sulfuric acid was 62 wt %, the reaction temperature was 130° C., the reaction time was 2 hour, and the weight ratio of sulfuric acid to mixed rare earth concentrate from Baiyenebo was 2.5:1.
  • the concentration of rare earth sulfate in the aqueous leaching liquor was 32.5-33 g/L calculated based on REO.
  • the decomposition rate of bastnaesite was 96-98%, and the decomposition rate of REO in the mixed rare earth concentrate from Baiyenebo was 58-60%, calculated based on the F content in the aqueous leaching residue.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Organic Chemistry (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Metallurgy (AREA)
  • Environmental & Geological Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

A method for treating fluorine-containing rare earth mineral particles may include mixing a first batch of the fluorine-containing rare earth mineral particles with a first sulfuric acid solution in a weight ratio in the range of 2-10:1 of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles, and heating the mixture to cause a liquid-solid reaction. The solid phase and liquid phase may be separated after the reaction to obtain an acid filtrate and an acid residue. The acid residue may be leached with water to obtain an aqueous leaching liquor that comprises a rare earth sulfate and an aqueous leaching residue. A second sulfuric acid solution may be added to the acid filtrate in an amount such that the sulfuric acid concentration of the acid filtrate is 40-85 wt %.

Description

TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for treating fluorine-containing rare earth mineral particles, in particular to a method for treating bastnaesite-containing rare earth mineral particles.
BACKGROUND OF THE INVENTION
Rare earth minerals mainly exist in the form of bastnaesite, mixed rare earth concentrate (bastnaesite and monazite), beach placer (monazite) and weathing crust strain amass-type rare earth ore. The representatives of bastnaesite are from Mountain Pass mine in the United States, Mianning rare earth mine in Sichuan Province and Weishanhu mine in Shandong Province in China. The typical representative of mixed type rare earth mineral is Baiyenebo rare earth minerals from Baotou area in Inner Mongolia in China. Therefore, it is of great significance to study the smelting separation technology of bastnaesite minerals. At present, the smelting technology of bastnaesite or bastnaesite in mixed type rare earth minerals has attracted more and more attention.
In one aspect, rare earth resources can be extracted with an air oxidizing roasting-hydrochloric acid dissolution technology. Bastnaesite mineral is decomposed into rare earth fluoride and rare earth oxide by oxidizing roasting. The concentration of hydrochloric acid and process of adding hydrochloric acid are controlled when the roasted ores are preferentially dissolved with hydrochloric acid, so as to extract trivalent rare earth and preliminarily separate from tetravalent cerium. Components such as cerium fluoride and cerium dioxide are retained in the residue, and can be used to prepare low-grade ferrosilicon alloy, or to extract tetravalent cerium with concentrated hydrochloric acid under the action of thiourea reductant. This process is widely used in the treatment of bastnaesite from Mianning in Sichuan Province. It can simply recover valuable rare earth at low cost. The problem of the above technical solution is that fluorine resources are not effectively used and rare earth resources are not completely extracted.
In another aspect, rare earth resources can be extracted with air oxidizing roasting-sulfuric acid dissolution technology. CN1683568A discloses a method of treating bastnaesite and separating cerium. Firstly, the bastnaesite concentrate is oxidizing roasted at 300-1000° C. to obtain bastnaesite calcine; the rare earth is leached out from the bastnaesite calcine with sulfuric acid, which is subjected to separation and reduction by coordination precipitant to separate trivalent rare earth elements from tetravalent rare earth elements, and to separate tetravalent cerium from tetravalent thorium. The problem of the above technical solution is that the bastnaesite concentrate must be oxidizing roasted at high temperature, and thus the process is too complicated.
In addition, there are a large amount of bastnaesite in the mixed type rare earth minerals, 90% of which are subjected to decomposition by concentrated sulfuric acid roasting process at high temperature. The mixed type rare earth minerals and concentrated sulfuric acid are roasted at high temperature of 500-1000° C. During the process, rare earth minerals and concentrated sulfuric acid contact and react, the solid-liquid phase changes into solid phase very quickly, and the reaction efficiency is very high. Therefore, the reaction makes high requirements on the particle size of raw mineral materials. When the size of mineral particles is greater than 200 mesh, the reaction rate will rapidly drop or the reaction will be terminated after a reaction on the surface is over. At the same time, in the reaction process, elements of fluorine and silicon in minerals and sulfur oxides from sulfuric acid decomposition enter the tail gas system, which makes it difficult to recycle fluorine resources.
CN106978532A discloses a method for extracting rare earth, fluorine and thorium from fluorine-contained rare earth minerals by concentrated sulfuric acid. The method comprises the following steps: the fluorine-contained rare earth minerals are mixed with the concentrated sulfuric acid; single fluorine-contained rare earth minerals or mixed rare earth concentrates contain 50-70 mass % of rare earth oxides; H2SO4 of the concentrated sulfuric acid is more than 90 mass %; the weight ratio of the fluorine-contained rare earth minerals to the concentrated sulfuric acid is 1:0.6-1.0; a mixture is fired for 120-300 min under the condition of 120-180° C.; a reaction product is leached with water, and then aqueous leaching liquor is neutralized to reach a pH value of 3.5-4.5 to form sulfuric acid rare earth solution and iron thorium enriched matters. Under the conditions of extremely low ratio of acid to minerals (the ratio of acid to minerals is 0.6-1.0:1) and extremely low reaction temperature (the temperature is 120-180° C.), the above technical solution realizes the transformation from solid-liquid phase to solid-solid phase, increases the reaction time, and realizes the preferential decomposition of bastnaesite. However, there are still the following problems in the above technical solution: first, it is difficult to control the end point of solid-solid phase reaction in the reaction process, and the decomposition rate of rare earth minerals must be ensured by recovering undecomposed minerals; second, when the process cannot be properly controlled, the reaction is terminated when the acidity of residual acid in the roasted minerals is very high, and a large amount of neutralizer is consumed in the process of aqueous leaching and impurity removal, with a waste of sulfuric acid.
CN102534269A discloses a method for comprehensively recycling various rare earth from rare earth materials containing fluorine, comprising the following steps: a. stirring the rare earth materials containing the fluorine with sulfuric acid, wherein hydrofluoric acid gas generated in the stirring process is used for preparing cryolite or hydrofluoric acid; b. leaching the stirred materials with water to obtain sulfuric rare earth solution. In the above technical solution, the sulfuric acid in step a is sulfuric acid with a concentration greater than 98%; the weight ratio of rare earth oxide in the rare earth material containing fluorine and sulfuric acid is 1:1.5-2; the addition amount of water during aqueous leaching in step b is controlled so that the concentration of rare earth in the aqueous leaching liquor is controlled at 90-110 g/L. Because the rare earth material containing fluorine and sulfuric acid react violently and release heat in the mixing process, the materials have already been in a semi-dry state. The above technical solution still has the following problems: first, due to too high concentration of sulfuric acid during mixing the reaction between concentrated sulfuric acid and bastnaesite is violent followed by a reaction rate changing greatly, so that it is difficult to control the reaction; second, the rare earth materials containing fluorine and sulfuric acid are mixed to form a semi-dry state, so the sulfuric acid is not easy to be recycled; third, it can treat only the activated bastnaesite after calcination or other reactions, but not the inactivated bastnaesite or mixed type rare earth concentrate.
In view of the defects of the prior arts, it is necessary to develop a method for treating the fluorine-containing rare earth mineral particles. The fluorine-containing rare earth mineral particles are decomposed by the liquid-solid phase mixing reaction in a lower concentration of sulfuric acid solution at a lower temperature, so as to realize the rapid decomposition of the fluorine-containing rare earth mineral particles. In addition, the reaction is easy to be controlled, and the residual acid resources are recycled.
SUMMARY OF THE INVENTION
In view of this, the purpose of the present invention is to provide a method for treating fluorine-containing rare earth mineral particles, wherein absolute excess sulfuric acid solution with a lower concentration is used to decompose the fluorine-containing rare earth mineral particles by liquid-solid phase mixing reaction at a lower temperature, so as to realize the rapid decomposition of fluorine-containing rare earth mineral particles. In addition, the reaction is easy to be controlled, and the residual acid resources are recycled.
The following technical solution is utilized in the present invention to achieve the above purposes.
The present invention provides a method for treating fluorine-containing rare earth mineral particles, comprising the following steps:
(1) mixing the first batch of fluorine-containing rare earth mineral particles with the first sulfuric acid solution according to the weight ratio of 2-10:1 of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles, and then heating the mixture for liquid-solid reaction, condensing and absorbing steam through a tail gas system, wherein a sulfuric acid concentration of the first sulfuric acid solution is 40-85 wt %;
(2) after the reaction, separating solid phase and liquid phase to obtain acid filtrate and acid residue;
(3) leaching the acid residue with water to obtain aqueous leaching liquor of rare earth sulfate and aqueous leaching residue;
(4) adding the second sulfuric acid solution to the acid filtrate so that the sulfuric acid concentration of the acid filtrate is 40-85 wt %; and then circularly executing the steps (1)-(3) for treating the ith batch of fluorine-containing rare earth mineral particles, wherein the character “i” is a natural number greater than or equal to 2;
wherein the first batch of fluorine-containing rare earth mineral particles and the ith batch of fluorine-containing rare earth mineral particles are rare earth mineral particles without performing roasting decomposition.
According to the method of the present invention, preferably, in step (1), the liquid-solid reaction is performed under continuous stirring, the reaction temperature is 100-180° C., and the reaction time is 0.5-5 hours.
According to the method of the present invention, preferably, in step (1), the liquid-solid reaction is performed under continuous stirring, the reaction temperature is 120-180° C., and the reaction time is 0.5-2 hours.
According to the method of the present invention, preferably, in step (1), the weight ratio of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is 3-8:1.
According to the method of the present invention, preferably, the first batch of fluorine-containing rare earth mineral particles and the ith batch of fluorine-containing rare earth mineral particles are selected from one or two of the following: (A) bastnaesite, (B) mixed type rare earth concentrate of bastnaesite and monazite.
According to the method of the present invention, preferably, the first batch of fluorine-containing rare earth mineral particles and the ith batch of fluorine-containing rare earth mineral particles have a particle size of less than 150 mesh.
According to the method of the present invention, preferably, the first batch of fluorine-containing rare earth mineral particles and the ith batch of fluorine-containing rare earth mineral particles have a particle size of less than 200 mesh.
According to the method of the present invention, preferably, in step (1), the sulfuric acid concentration of the first sulfuric acid solution is 50-85 wt %; and in step (4) the second sulfuric acid solution is added to the acid filtrate so that the sulfuric acid concentration of the acid filtrate is 50-85 wt %.
According to the method of the present invention, preferably, in step (1), the sulfuric acid concentration of the first sulfuric acid solution is 60-75 wt %; and in step (4), the second sulfuric acid solution is added to the acid filtrate so that the sulfuric acid concentration of the acid filtrate is 60-75 wt %.
According to the method of the present invention, preferably, in step (3), the concentration of the rare earth sulfate in the rare earth sulfate aqueous leaching liquor is 20-45 g/L, calculated based on the rare earth oxide REO.
In the present invention, absolute excess sulfuric acid solution with a lower concentration is used to decompose the fluorine-containing rare earth mineral particles by liquid-solid phase mixing reaction at a lower temperature, so as to realize the rapid decomposition of the fluorine-containing rare earth mineral particles. In addition, the reaction is easy to be controlled, and the residual acid resources are recycled. In the present invention, the liquid-solid reaction is circularly applied to directly decompose the inactivated bastnaesite or mixed type rare earth concentrate; thereby the cost of rare earth extraction is significantly reduced. According to the preferred technical solution of the invention, the weight ratio of sulfuric acid to fluorine-containing rare earth mineral particles is 3-5:1, and the following technical problem is solved by using absolute excess sulfuric acid solution with a lower concentration: a great change in reaction rate of concentrated sulfuric acid and bastnaesite, and it is difficult to control the reaction.
DETAIL DESCRIPTION OF THE INVENTION
The present invention will be further explained in combination with specific embodiments, but the protection scope of the present invention is not limited thereto.
In the present invention, “select from” or “selected from” refers to the selection of individual components or the combination of two (or more) components.
The method for treating fluorine-containing rare earth mineral particles according to the present invention, comprising the following steps: (1) performing liquid-solid reaction of the first batch of fluorine-containing rare earth mineral particles and the first sulfuric acid solution; (2) separating solid phase and liquid phase to obtain acid filtrate and acid residue; (3) treating the acid residue; (4) adding the second sulfuric acid solution to the acid filtrate, and then circularly executing the steps (1)-(3) for treating the ith batch of fluorine-containing rare earth mineral particles, wherein “i” is a natural number greater than or equal to 2.
In step (1) of the method according to the present invention, both the first batch of fluorine-containing rare earth mineral particles and the ith batch of fluorine-containing rare earth mineral particles are selected from one or two of the following: (A) bastnaesite, (B) mixed type rare earth concentrate of bastnaesite and monazite. The first batch of fluorine-containing rare earth mineral particles and the ith batch of fluorine-containing rare earth mineral particles are rare earth mineral particles without performing roasting decomposition. The method of the present invention is suitable to fluorine-containing rare earth mineral particles that have not been subjected to roasting decomposition; thereby the cost of rare earth extraction can be significantly reduced.
In step (1) of the method according to the present invention, the mixed raw material is the first batch of fluorine-containing rare earth mineral particles and the first sulfuric acid solution. The sulfuric acid concentration of the first sulfuric acid solution is 40-85 wt %; preferably, the sulfuric acid concentration of the first sulfuric acid solution is 50-85 wt %; more preferably, the sulfuric acid concentration of the first sulfuric acid solution is 60-75 wt %. The weight ratio of the sulfuric acid (i.e., solute) in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is 2-10:1; preferably, the weight ratio of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is 3-8:1; more preferably, the weight ratio of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is 3-5:1. According to an embodiment of the present invention, the weight ratio of the sulfuric acid in the first sulfuric acid solution to the bastnaesite from Mianning in Sichuan Province is 3.4-3.8:1. According to another embodiment of the present invention, the weight ratio of the sulfuric acid in the first sulfuric acid solution to the mixed rare earth concentrate from Baiyenebo is 4-5:1.
In step (1) of the method according to the present invention, the liquid-solid reaction is performed under continuous stirring. General mechanical agitation may be used. The liquid-solid reaction temperature is 100-180° C.; preferably, the liquid-solid reaction temperature is 120-180° C.; more preferably, the liquid-solid reaction temperature is 130-180° C. The liquid-solid reaction time is 0.5-5 hours; preferably, the liquid-solid reaction time is 0.5-3 hours; more preferably, the liquid-solid reaction time is 0.5-2 hours. Steam may be generated during liquid-solid reaction, and it contains a lot of hydrofluoric acid gas. The hydrofluoric acid gas is condensed and absorbed through the tail gas system to obtain hydrofluoric acid products. According to an embodiment of the present invention, the liquid-solid reaction temperature is 140-150° C., and the reaction time is 1-1.5 hours. According to another embodiment of the present invention, for the first batch of mixed rare earth concentrate from Baiyenebo, the liquid-solid reaction temperature is 170-180° C., and the reaction time is 0.5-1 hours; for the second batch of mixed rare earth concentrate from Baiyenebo, the liquid-solid reaction temperature is 150-160° C., and the reaction time is 1-1.5 hours; for the third batch of mixed rare earth concentrate from Baiyenebo, the liquid-solid reaction temperature is 130-135° C., and the reaction time is 1.5-2 hours; for each one of the following 15 rounds of circular execution, the liquid-solid reaction temperature is 130-135° C., and the reaction time is 1.5-2 hours.
In step (2) of the method according to the present invention, solid phase and liquid phase are separated after the liquid-solid reaction to obtain acid filtrate and acid residue. Rare earth products can be obtained by treating the acid residue. In the liquid-solid reaction, absolute excess sulfuric acid solution with a lower concentration is used. The sulfuric acid solution is of a greatly excessive amount. The fluorine-containing rare earth mineral particles are completely immersed in the sulfuric acid solution. There are relatively large amount of sulfuric acid solutions left after the reaction, and the remaining sulfuric acid solution (acid filtrate) can be recycled. According to an embodiment of the present invention, in the treatment of the first batch of bastnaesite from Mianning in Sichuan Province, solid phase and liquid phase are separated after the reaction, and the first batch of acid filtrate and the first batch of acid residue are obtained. According to another embodiment of the present invention, in the treatment of the first batch of mixed rare earth concentrate from Baiyenebo, solid phase and liquid phase are separated after the reaction, and the first batch of acid filtrate and the first batch of acid residue are obtained.
In step (3) of the method according to the present invention, the acid residue is leached with water to obtain aqueous leaching liquor of rare earth sulfate and aqueous leaching residue. In case of that fluorine-containing rare earth mineral particles are bastnaesite, the bastnaesite decomposition rate is ≥95%, calculated based on the rare earth oxide (REO) in the aqueous leaching residue; in case of that fluorine-containing rare earth mineral particles are the mixed type rare earth concentrate of bastnaesite and monazite, the bastnaesite decomposition rate is ≥95%, calculated based on the F content in the aqueous leaching residue. According to an embodiment of the present invention, the fluorine-containing rare earth mineral particles are bastnaesite from Mianning in Sichuan Province, the bastnaesite decomposition rate is ≥96% in the multi-round of circular execution, calculated based on the rare earth oxide (REO) in the aqueous leaching residue. According to another embodiment of the present invention, the fluorine-containing rare earth mineral particles are the mixed type rare earth concentrate from Baiyenebo, the bastnaesite decomposition rate is ≥96% in the multi-round of circular execution, calculated based on the F content in the aqueous leaching residue.
In step (3) of the method according to the present invention, when the acid residue is leached with water, the amount of water is 10-50 times of the weight of the first batch of fluorine-containing rare earth mineral particles; preferably, the amount of water is 10-35 times of the weight of the first batch of fluorine-containing rare earth mineral particles; more preferably, the amount of water is 15-25 times of the weight of the first batch of fluorine-containing rare earth mineral particles. According to an embodiment of the present invention, liquid-solid reaction is performed circularly to decompose bastnaesite from Mianning in Sichuan Province, in which the first batch of acid residue is leached with 1500-2000 mL of water. The amount of water is 15-20 times of the weight of bastnaesite from Mianning in Sichuan Province. According to another embodiment of the present invention, liquid-solid reaction is performed circularly to decompose the mixed rare earth concentrate from Baiyenebo, in which the first batch of acid residue is leached with 1500-2000 mL of water. The amount of water is 15-20 times of the weight of the mixed rare earth concentrate from Baiyenebo.
In the aqueous leaching liquor of rare earth sulfate, the concentration of rare earth sulfate is 20-45 g/L calculated based on the rare earth oxide (REO), preferably 25-40 g/L, more preferably 30-35 g/L. According to a specific embodiment of the present invention, liquid-solid reaction is performed circularly to decompose bastnaesite from Mianning in Sichuan Province, the first batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 25.0-26.7 g/L calculated based on the rare earth oxide (REO); the second batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 28.0-30.2 g/L calculated based on the rare earth oxide (REO); the third batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 32-34.7 g/L calculated based on the rare earth oxide (REO); the fourth batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 32-33.6 g/L calculated based on the rare earth oxide (REO); after the following 4-10 rounds of circular execution, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 32.5-33 g/L calculated based on the rare earth oxide (REO). According to another specific embodiment of the present invention, liquid-solid reaction is performed circularly to decompose the mixed rare earth concentrate from Baiyenebo, the first batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 22-23.3 g/L calculated based on the rare earth oxide (REO); the second batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 28.0-30.7 g/L calculated based on the rare earth oxide (REO); the third batch of acid residue is leached with 1500-2000 mL of water, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 32-34.5 g/L calculated based on the rare earth oxide (REO); after the following 15-18 rounds of circular execution, the concentration of rare earth sulfate in the aqueous leaching liquor of rare earth sulfate is 32.5-33 g/L calculated based on the rare earth oxide (REO).
In step (4) of the method according to the present invention, after the second sulfuric acid solution is added to the acid filtrate, circularly executing the steps (1)-(3) for treating the ith batch of fluorine-containing rare earth mineral particles. The character “i” is a natural number greater than or equal to 2, for example, it can be 2, 3, 4, 5, 6, 7, 8 and so on. Before each round of liquid-solid reaction, the initial mass fraction of sulfuric acid solution is 40-85 wt %; preferably, before each round of liquid-solid reaction, the initial mass fraction of sulfuric acid solution is 50-85 wt %; more preferably, before each round of liquid-solid reaction, the initial mass fraction of sulfuric acid solution is 60-75 wt %. When the second sulfuric acid solution is added, its addition amount is based on the actual consumption of sulfuric acid in the previous round of liquid-solid reaction. The sulfuric acid concentration of the second sulfuric acid solution is ≥90 wt %; preferably, the sulfuric acid concentration of the second sulfuric acid solution is ≥95 wt %; more preferably, the sulfuric acid concentration of the second sulfuric acid solution is ≥98 wt %. According to a specific embodiment of the present invention, 60-72 g of concentrated sulfuric acid with concentration of 98 wt % is added to the first batch of acid filtrate, calculated based on treating 100 g of the second batch of bastnaesite. 60-68 g of concentrated sulfuric acid with concentration of 98 wt % is added into the second batch of acid filtrate, calculated based on treating 100 g of the third batch of bastnaesite. 65-72 g of concentrated sulfuric acid with concentration of 98 wt % is added into the third batch of acid filtrate, calculated based on treating 100 g of the fourth batch of bastnaesite. For the following 4-8 rounds of circular execution, 53-55 g of concentrated sulfuric acid with concentration of 98 wt % is added into the acid filtrate in the last round of each round, calculated based on treating 100 g of the ith batch of bastnaesite.
In step (4) of the method according to the present invention, the temperature of liquid-solid reaction in each circular execution is 100-180° C., preferably 120-180° C., more preferably 130-180° C. The time of liquid-solid reaction in each circular execution is 0.5-5 hours, preferably 0.5-3 hours, more preferably 0.5-2 hours. Steam may be generated during liquid-solid reaction of each circular execution, and it contains a lot of hydrofluoric acid gas. The hydrofluoric acid gas is condensed and absorbed through the tail gas system to obtain hydrofluoric acid products. In each circular execution, solid phase and liquid phase are separated after the liquid-solid reaction, and acid filtrate and acid residue are obtained. Rare earth products can be obtained by treating the acid residue.
The method for treating fluorine-containing rare earth mineral particles according to the present invention also comprises the step of crushing fluorine-containing rare earth mineral particles.
In the step of crushing fluorine-containing rare earth mineral particles, the fluorine-containing rare earth mineral particles are crushed to a particle size of less than 150 mesh; preferably, the fluorine-containing rare earth mineral particles are crushed to a particle size of less than 200 mesh. This can facilitate the decomposition of the fluorine-containing rare earth mineral particles. If the fluorine-containing rare earth mineral particles have a particle size of less than 150 mesh, they need not to be crushed, and thus the crushing procedure can be omitted. According to a specific embodiment of the present invention, the bastnaesite is crushed to a particle size of less than 150 mesh to obtain the bastnaesite particles. According to another specific embodiment of the present invention, the particle size of mixed type rare earth concentrate of bastnaesite and monazite is less than 200 mesh.
Example 1
The crushing of the bastnaesite from Mianning in Sichuan Province: the bastnaesite from Mianning in Sichuan Province with REO content of 68.2 wt % was crushed to a particle size of less than 150 mesh, and the bastnaesite particles were obtained.
(1) Treatment of the First Batch of Bastnaesite from Mianning in Sichuan Province
100 g of crushed bastnaesite from Mianning in Sichuan Province without performing roasting decomposition was mixed with 485 g of sulfuric acid solution with a concentration of 70 wt % (the weight ratio of sulfuric acid to bastnaesite is 3.4:1); the mixture was heated with stirring, and reacted at 140° C. for 1 hour, and steam was condensed and absorbed through tail gas system to obtain hydrofluoric acid products. The solid phase and the liquid phase were separated after the liquid-solid reaction, and the first batch of acid filtrate and the first batch of acid residue were obtained. The first batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor of rare earth sulfate and the aqueous leaching residue were obtained. The concentration of rare earth sulfate in the aqueous leaching liquor was 26.7 g/L calculated based on REO. The decomposition rate of bastnaesite is 98.2% calculated based on REO in the aqueous leaching residue.
(2) Treatment of the Second Batch of Bastnaesite
72 g of concentrated sulfuric acid with a concentration of 98 wt % was added to the first batch of acid filtrate under stirring, till the concentration of sulfuric acid was 70 wt %. 100 g of the second batch of bastnaesite from Mianning in Sichuan Province with REO content of 68.2 wt % was treated. The treatment conditions of acid amount, initial concentration of sulfuric acid, reaction temperature and reaction time were identical to those in the treatment of the first batch of bastnaesite from Mianning in Sichuan Province. The solid phase and the liquid phase were separated after the liquid-solid reaction, and the second batch of acid filtrate and the second batch of acid residue were obtained. The second batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained. The concentration of rare earth sulfate in the aqueous leaching liquor was 30.2 g/L calculated based on REO. The decomposition rate of bastnaesite is 96.7% calculated based on REO in the aqueous leaching residue.
(3) Treatment of the Third Batch of Bastnaesite
68 g of concentrated sulfuric acid with a concentration of 98 wt % was added to the second batch of acid filtrate under stirring, till the concentration of sulfuric acid was 70 wt %. The third batch of bastnaesite from Mianning in Sichuan Province with REO content of 68.2 wt % was treated. The treatment conditions of acid amount, initial concentration of sulfuric acid, reaction temperature and reaction time were identical to those in the treatment of the first batch of bastnaesite from Mianning in Sichuan Province. The solid phase and the liquid phase were separated after the liquid-solid reaction, and the third batch of acid filtrate and the third batch of acid residue were obtained. The third batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained. The concentration of rare earth sulfate in the aqueous leaching liquor was 34.7 g/L calculated based on REO. The decomposition rate of bastnaesite is 96.3% calculated based on REO in the aqueous leaching residue.
(4) Treatment of the Fourth Batch of Bastnaesite
72 g of concentrated sulfuric acid with a concentration of 98 wt % was added to the third batch of acid filtrate under stirring, till the concentration of sulfuric acid was 70 wt %. The fourth batch of bastnaesite from Mianning in Sichuan Province with REO content of 68.2 wt % was treated. The treatment conditions of acid amount, initial concentration of sulfuric acid, reaction temperature and reaction time were identical to those in the treatment of the first batch of bastnaesite from Mianning in Sichuan Province. The solid phase and the liquid phase were separated after the liquid-solid reaction, and the fourth batch of acid filtrate and the fourth batch of acid residue were obtained. The fourth batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained. The concentration of rare earth sulfate in the aqueous leaching liquor was 33.6 g/L calculated based on REO. The decomposition rate of bastnaesite is 96.5% calculated based on REO in the aqueous leaching residue.
(5) Circularly Executing the Steps for Treating the ith Batch of Bastnaesite
After four other rounds of circular execution, treating conditions for each round of circular execution was as follows: the addition amount of concentrated sulfuric acid with a concentration of 98 wt % was 53-55 g, the initial concentration of sulfuric acid was 70 wt %, the reaction temperature was 140° C., and the reaction time was 1 hour. The concentration of rare earth sulfate in the aqueous leaching liquor was 32.5-33 g/L calculated based on REO.
Example 2
The mixed rare earth concentrate from Baiyenebo: the mixed rare earth concentrate from Baiyenebo has a REO content of 61.9 wt % and a particle size of less than 200 mesh. The mixed rare earth concentrate from Baiyenebo is the mixed type rare earth concentrate of bastnaesite and monazite.
(1) Treatment of the First Batch of Mixed Rare Earth Concentrate from Baiyenebo
100 g of the mixed rare earth concentrate from Baiyenebo without performing roasting decomposition was mixed with 590 g of sulfuric acid solution with a concentration of 85 wt % (the weight ratio of sulfuric acid to mixed rare earth concentrate from Baiyenebo is 5:1); the mixture was heated with stirring, and reacted at 180° C. for 0.5 hour, and steam was condensed and absorbed through tail gas system to obtain hydrofluoric acid products. The solid phase and the liquid phase were separated after the liquid-solid reaction, and the first batch of acid filtrate and the first batch of acid residue were obtained. The first batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained. The concentration of rare earth sulfate in the aqueous leaching liquor was 23.3 g/L calculated based on REO. The decomposition rate of bastnaesite is 97.5% calculated based on the F content in the aqueous leaching residue.
(2) Treatment of the Second Batch of Mixed Rare Earth Concentrate from Baiyenebo
100 g of the second batch of mixed rare earth concentrate from Baiyenebo with REO content of 61.9 wt % was treated with the first batch of acid filtrate under stirring. The initial concentration of sulfuric acid was 73 wt %, the reaction temperature was 150° C., and the reaction time was 1 hour. The solid phase and the liquid phase were separated after the liquid-solid reaction, and the second batch of acid filtrate and the second batch of acid residue were obtained. The second batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained. The concentration of rare earth sulfate in the aqueous leaching liquor was 30.7 g/L calculated based on REO. The decomposition rate of bastnaesite is 96.2% calculated based on the F content in the aqueous leaching residue.
(3) Treatment of the Third Batch of Mixed Rare Earth Concentrate from Baiyenebo
100 g of the third batch of mixed rare earth concentrate from Baiyenebo with REO content of 61.9 wt % was treated with the second batch of acid filtrate under stirring. The initial concentration of sulfuric acid was 64 wt %, the reaction temperature was 130° C., and the reaction time was 2 hour. The solid phase and the liquid phase were separated after the liquid-solid reaction, and the third batch of acid filtrate and the third batch of acid residue were obtained. The third batch of acid residue was leached with 2000 mL of water, and the aqueous leaching liquor and the aqueous leaching residue of rare earth sulfate were obtained. The concentration of rare earth sulfate in the aqueous leaching liquor was 34.5 g/L calculated based on REO. The decomposition rate of bastnaesite is 97.7% calculated based on the F content in the aqueous leaching residue.
(4) Circularly Executing the Steps for Treating the ith Batch of Mixed Rare Earth Concentrate from Baiyenebo
After other 15 rounds of circular execution, treating conditions for each round of circular execution was as follows: the addition amount of concentrated sulfuric acid with a concentration of 98 wt % was 53-55 g, the initial concentration of sulfuric acid was 62 wt %, the reaction temperature was 130° C., the reaction time was 2 hour, and the weight ratio of sulfuric acid to mixed rare earth concentrate from Baiyenebo was 2.5:1. The concentration of rare earth sulfate in the aqueous leaching liquor was 32.5-33 g/L calculated based on REO. The decomposition rate of bastnaesite was 96-98%, and the decomposition rate of REO in the mixed rare earth concentrate from Baiyenebo was 58-60%, calculated based on the F content in the aqueous leaching residue.
The present invention is not limited by the above embodiments. All variations, modifications and replacements to the disclosed embodiments which are apparent to those skilled in the art and do not depart from the essence of the present invention fall in the scope of the present invention.

Claims (8)

What is claimed is:
1. A method for treating fluorine-containing rare earth mineral particles, comprising:
(1) mixing a first batch of the fluorine-containing rare earth mineral particles with a first sulfuric acid solution in a weight ratio in the range of 2-10:1 of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles, and heating the mixture to cause a liquid-solid reaction;
(2) separating the solid phase and liquid phase after the reaction to obtain an acid filtrate and an acid residue;
(3) leaching the acid residue with water to obtain an aqueous leaching liquor that comprises a rare earth sulfate, and an aqueous leaching residue;
(4) adding a second sulfuric acid solution to the acid filtrate in an amount such that the sulfuric acid concentration of the acid filtrate is 50-85 wt %; and then performing the steps (1)-(3) i times for treating further batches of fluorine-containing rare earth mineral particles up to the ith batch, wherein the character “i” is a natural number greater than or equal to 2 and wherein each performance of the steps (1)-(3) treats one batch;
wherein the fluorine-containing rare earth mineral particles have not been subjected to roasting decomposition,
wherein the liquid-solid reaction generates steam which is condensed and absorbed through a tail gas system, and
wherein a sulfuric acid concentration of the first sulfuric acid solution is 50-85 wt %,
wherein the concentration of the rare earth sulfate in the aqueous leaching liquor is 20-45 g/L, as calculated based on a rare earth oxide.
2. The method according to claim 1, wherein the liquid-solid reaction is performed under continuous stirring, a reaction temperature is 100-180° C., and a reaction time is 0.5-5 hours.
3. The method according to claim 1, wherein the liquid-solid reaction is performed under continuous stirring, a reaction temperature is 120-180° C., and a reaction time is 0.5-2 hours.
4. The method according to claim 1, wherein the weight ratio of the sulfuric acid in the first sulfuric acid solution to the first batch of fluorine-containing rare earth mineral particles is in the range of 3-8:1.
5. The method according to claim 1, wherein the fluorine-containing rare earth mineral particles are selected from one or two of the group consisting of bastnaesite and a mixed type rare earth concentrate of bastnaesite and monazite.
6. The method according to claim 5, wherein the fluorine-containing rare earth mineral particles have a particle size of less than 150 mesh.
7. The method according to claim 5, wherein the fluorine-containing rare earth mineral particles have a particle size of less than 200 mesh.
8. The method according to claim 1, wherein the sulfuric acid concentration of the first sulfuric acid solution is 60-75 wt %, and the second sulfuric acid solution is added to the acid filtrate in an amount such that the sulfuric acid concentration of the acid filtrate is 60-75 wt %.
US16/630,311 2018-09-14 2019-06-21 Method for treating fluorine-containing rare earth mineral particles Active 2040-05-17 US11427884B2 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201811072801.3 2018-09-14
CN201811072801.3A CN109022838B (en) 2018-09-14 2018-09-14 Method for treating fluorine-containing rare earth mineral particles
CN2018110728013 2018-09-14
PCT/CN2019/092296 WO2020052311A1 (en) 2018-09-14 2019-06-21 Method for processing fluorine-containing rare earth mineral particles

Publications (2)

Publication Number Publication Date
US20210062295A1 US20210062295A1 (en) 2021-03-04
US11427884B2 true US11427884B2 (en) 2022-08-30

Family

ID=64621614

Family Applications (1)

Application Number Title Priority Date Filing Date
US16/630,311 Active 2040-05-17 US11427884B2 (en) 2018-09-14 2019-06-21 Method for treating fluorine-containing rare earth mineral particles

Country Status (5)

Country Link
US (1) US11427884B2 (en)
EP (1) EP3663421B1 (en)
JP (1) JP6896139B2 (en)
CN (1) CN109022838B (en)
WO (1) WO2020052311A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109022838B (en) 2018-09-14 2020-03-06 包头稀土研究院 Method for treating fluorine-containing rare earth mineral particles
CN109487089A (en) * 2019-01-07 2019-03-19 江西理工大学 A kind of method of rare earth fluoride molten-salt electrolysis Slag treatment
CN111270092B (en) * 2020-02-07 2022-08-05 包头稀土研究院 Method for decomposing mixed rare earth ore
CN111187905A (en) * 2020-02-11 2020-05-22 包头稀土研究院 Method for decomposing mineral containing rare earth phosphate
CN111334662B (en) * 2020-04-10 2021-12-14 包头稀土研究院 Method for decomposing rare earth concentrate
CN112080654B (en) * 2020-09-25 2022-08-16 贵州省地质矿产中心实验室(贵州省矿产品黄金宝石制品质量检验站) Method for recovering acid and silicon from phosphorus rare earth chemical concentrate leachate
CN115057445B (en) * 2022-07-22 2023-11-24 包头稀土研究院 Production method of silicon fluorine hydrogen acid and treatment process of mixed rare earth concentrate
CN115744951A (en) * 2022-11-15 2023-03-07 江西理工大学 Resource utilization method of fluorine in rare earth molten salt electrolytic slag

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6090823A (en) 1983-10-24 1985-05-22 Asahi Chem Ind Co Ltd Method for recovering rare earth metallic sulfate
EP0418125A1 (en) * 1989-09-13 1991-03-20 Rhone-Poulenc Chimie Process for treating ores containing rare earths
CN1683568A (en) 2004-04-14 2005-10-19 北京方正稀土科技研究所有限公司 Sulfuric acid process for treating bastnaesite and separating and purifying cerium
CN102534269A (en) 2012-03-26 2012-07-04 乐山盛和稀土股份有限公司 Method for comprehensively recycling various rare earth from rare earth materials containing fluorine
CN106978532A (en) 2017-03-15 2017-07-25 包头稀土研究院 The method that the concentrated sulfuric acid extracts fluorine-containing rare-earth mineral middle rare earth, fluorine and thorium
CN109022838A (en) 2018-09-14 2018-12-18 包头稀土研究院 The processing method of fluorine-containing rare-earth mineral particle

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1173050C (en) * 2002-09-25 2004-10-27 包头稀土研究院 Low-temperature roasting and decomposing process of rare earth heading concentrated sucfuric acid
CN1286995C (en) * 2004-03-08 2006-11-29 中国有色工程设计研究总院 Mixed rare earth concentrate decomposition method
CN1847419A (en) * 2005-04-05 2006-10-18 内蒙古包钢稀土高科技股份有限公司 Stepped sulfuric acid treatment and roasting process for decomposing Baotou RE ore concentrate
CN101633980A (en) * 2008-07-23 2010-01-27 甘肃稀土新材料股份有限公司 Roasting process of sulfuric acid of rare-earth ore
CN103374652B (en) * 2012-09-29 2015-04-22 有研稀土新材料股份有限公司 Method for comprehensively recycling rare earth and fluorine in process of treating bastnaesite
CN104946887A (en) * 2015-07-22 2015-09-30 中国恩菲工程技术有限公司 Method for treating bastnasite concentrate
WO2017100933A1 (en) * 2015-12-16 2017-06-22 Quest Rare Minerals Ltd. Rare earth ore processing methods by acid mixing, sulphating and decomposing
CN106978531B (en) * 2017-03-15 2018-12-14 包头稀土研究院 The method that soda acid joint decomposes mixed rare earth concentrate
CN107475542B (en) * 2017-07-17 2021-03-16 中国恩菲工程技术有限公司 Method for treating rare earth concentrate

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6090823A (en) 1983-10-24 1985-05-22 Asahi Chem Ind Co Ltd Method for recovering rare earth metallic sulfate
EP0418125A1 (en) * 1989-09-13 1991-03-20 Rhone-Poulenc Chimie Process for treating ores containing rare earths
JPH03170625A (en) 1989-09-13 1991-07-24 Rhone Poulenc Chim Treatment of the ore containing rare earth elements
CN1683568A (en) 2004-04-14 2005-10-19 北京方正稀土科技研究所有限公司 Sulfuric acid process for treating bastnaesite and separating and purifying cerium
CN102534269A (en) 2012-03-26 2012-07-04 乐山盛和稀土股份有限公司 Method for comprehensively recycling various rare earth from rare earth materials containing fluorine
CN106978532A (en) 2017-03-15 2017-07-25 包头稀土研究院 The method that the concentrated sulfuric acid extracts fluorine-containing rare-earth mineral middle rare earth, fluorine and thorium
CN109022838A (en) 2018-09-14 2018-12-18 包头稀土研究院 The processing method of fluorine-containing rare-earth mineral particle
JP6896139B2 (en) 2018-09-14 2021-06-30 パオトウ リサーチ インスティチュート オブ レア アース Treatment method for fluorine-containing rare earth mineral particles

Non-Patent Citations (16)

* Cited by examiner, † Cited by third party
Title
CN-106978532-A Translation (Year: 2017). *
Decision to Grant issued in corresponding CN Application No. 201811072801.3 with English translation dated Feb. 3, 2020 (3 pages).
Decision to Grant issued in corresponding EP Application No. 19823875.0 dated Dec. 16, 2021 (3 pages).
Decision to Grant issued in corresponding JP Application No. 2020-500133 with English translation dated May 20, 2021 (5 pages).
EP-0418125-A1 Translation (Year: 1991). *
Extended European Search Report issued in corresponding EP Application No. 19823875.0 dated Nov. 3, 2020 (11 pages).
International Search Report issued in International Application No. PCT/CN2019/092296 dated Sep. 16, 2019 (4 pages).
JP-60090823-A Translation (Year: 1985). *
Kim, Rina et al. "Optimization of Acid Leaching of Rare-Earth Elements from Mongolian Apatite-Based Ore" Minerals 2016, 6, 63 (15 pages).
Notification of Publication issued in corresponding EP Application No. 19823875.0 dated May 13, 2020 (2 pages).
Office Action issued in corresponding CN Application No. 201811072801.3 with English translation dated Jul. 17, 2019 (7 pages).
Office Action issued in corresponding JP Application No. 2020-500133 with English translation dated Jan. 6, 2021 (7 pages).
Search Report issued in corresponding CN Application No. 201811072801.3 dated Jan. 10, 2020 (2 pages).
Search Report issued in corresponding CN Application No. 201811072801.3 dated Jul. 4, 2019 (3 pages).
Supplementary European Search Report issued in corresponding EP Application No. 19823875.0 dated Nov. 20, 2020 (1 page).
Written Opinion issued in International Application No. PCT/CN2019/092296 dated Sep. 16, 2019 (4 pages).

Also Published As

Publication number Publication date
JP2021501828A (en) 2021-01-21
EP3663421A1 (en) 2020-06-10
CN109022838A (en) 2018-12-18
WO2020052311A1 (en) 2020-03-19
CN109022838B (en) 2020-03-06
JP6896139B2 (en) 2021-06-30
EP3663421A4 (en) 2020-12-02
US20210062295A1 (en) 2021-03-04
EP3663421B1 (en) 2022-01-12

Similar Documents

Publication Publication Date Title
US11427884B2 (en) Method for treating fluorine-containing rare earth mineral particles
CA3008040C (en) Rare earth ore processing methods by acid mixing, sulphating and decomposing
JP5938048B2 (en) Dissolution and recovery of at least one element of Nb or Ta and at least one element of other U or rare earth elements from ores and concentrates
Cheng et al. Dephosphorisation of western Australian iron ore by hydrometallurgical process
RU2618975C2 (en) System and method of extraction of rare earth elements
KR102553461B1 (en) System and process for selective rare earth extraction with sulfur recovery
CN110551902B (en) Method for recycling fayalite type slag resources
CN111394571B (en) Method for improving decomposition efficiency of rare earth mineral and sulfuric acid
CN107208177A (en) The acidleach of rare earth element is carried
CN114737066B (en) Method for extracting lithium from leaching residues of lithium ores
Aparajith et al. Recovery of enriched lead–silver residue from silver-rich concentrate of hydrometallurgical zinc smelter
JP7313430B2 (en) Method for recovery of rare earths
US4670228A (en) Process for the recovery of valuable metals, particularly rare earths and similar metals, from a carbonate-containing raw material
CN110079680B (en) Copper extraction method for complex copper oxide ores in various copper occurrence states
WO2021081590A1 (en) Vanadium recovery process
US4891061A (en) Process for treating speiss
AU2013325098A1 (en) Method for the recovery of metals from nickel bearing ores and concentrates
Chen et al. The Extraction of Zinc from Willemite by Calcified‐Roasting and Ammonia‐Leaching Process Based on Phase Reconstruction
US2640754A (en) Treatment of carnotite ore materials
US1807642A (en) Process fob recovery of manganese
JP6087360B2 (en) Selective base metal leaching from laterite ores
WO2023240343A1 (en) A process and system for extracting rare earth elements using high pulp density cracking
CN116970802A (en) Sulfating roasting process of single bastnaesite
CN109097557A (en) A method of recycling zinc from willemite resource
CN113122707A (en) Method for recovering gold by utilizing sulfuric acid residue to reinforce chlorination roasting

Legal Events

Date Code Title Description
FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY

AS Assignment

Owner name: BAOTOU RESEARCH INSTITUTE OF RARE EARTHS, CHINA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CUI, JIANGUO;WANG, ZHE;HOU, RUIEN;AND OTHERS;REEL/FRAME:051525/0614

Effective date: 20200108

Owner name: NATIONAL ENGINEERING RESEARCH CENTRE OF RUIKE RARE EARTH METALLURGY AND FUNCTION MATERIALS CO., LTD., CHINA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CUI, JIANGUO;WANG, ZHE;HOU, RUIEN;AND OTHERS;REEL/FRAME:051525/0614

Effective date: 20200108

FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO SMALL (ORIGINAL EVENT CODE: SMAL); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY

STPP Information on status: patent application and granting procedure in general

Free format text: APPLICATION DISPATCHED FROM PREEXAM, NOT YET DOCKETED

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS

STPP Information on status: patent application and granting procedure in general

Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT RECEIVED

STPP Information on status: patent application and granting procedure in general

Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED

STCF Information on status: patent grant

Free format text: PATENTED CASE